This invention relates to an arc suppression device which may be connected in parallel with existing power contactors to eliminate substantially arcing across the contacts thereof.
Semiconductor devices have been placed in parallel with the contacts of power contactors to reduce or suppress arcing during contact closure and opening, as shown in U.S. Pat. Nos. 3,260,894; 3,555,353; 3,639,808; 3,982,137 and 4,025,820.
In U.S. Pat. Nos. 3,260,894; 3,892,137 and 4,025,820, gating current to the semiconductor arc suppressing device is provided by an auxiliary contact connected mechanically to the movable contact of a power contactor. This auxiliary contact is designed to close prior to and open following the opening and closing of the power contacts so that the semiconductor device would be provided with gating current during that interval, but not while the main contacts were closed so that the semiconductor device would not be required to carry current continuously should the main contacts fail to close or close with an appreciable resistance therebetween.
In U.S. Pat. Nos. 3,553,353 and 3,639,808, the coil of the power contactor is used to provide gating current to the semiconductor arc suppression means.
In all of the above devices, some modification or redesign of the power contactor or its associated control circuitry is necessary in order to incorporate the arc suppression means.